Ultrasound Measurements of the Median Nerve at the Distal Wrist Crease Correlate With Electrodiagnostic Studies

Ultrasound Measurements of the Ulnar Nerve at the Medial Epicondyle Correlate With Electrodiagnostic Studies

BACKGROUND

Cubital tunnel syndrome is the second most common compressive neuropathy in the upper extremity and is commonly evaluated with electrodiagnostic studies (EDS). Ultrasound (US) has emerged as a potentially more efficient alternative to EDS. The purpose of this study is to evaluate whether measurements of the cross-sectional area (CSA) of the ulnar nerve at the elbow correlate with EDS results.

METHODS

This study was a prospective analysis of patients who presented with signs and symptoms consistent of cubital tunnel syndrome, who received USs of the ulnar nerve at the elbow and nerve conduction tests. Pearson correlation coefficients were used to evaluate the correlation between ulnar nerve CSA and electrodiagnostic data. t Tests were used to evaluate statistical differences between the mean ulnar nerve CSA of patients with positive or negative nerve conduction study results. Youden Index was used to calculate the optimal cut-off point for US CSA based on maximal sensitivity and specificity. Statistical significance was based on a two-sided P less than .05.

RESULTS

The association between increasing US CSA at the medial epicondyle with slowing of the conduction velocity of the ulnar motor nerve across the elbow was statistically significant (r = -0.35, P = .02). Patients with positive EDS tests had significantly larger nerve size than those with negative tests (all Ps < .03). A cut-off point of greater than or equal to 11 mm2 had a sensitivity of 70.83% and specificity of 66.67%.

CONCLUSIONS

Larger ulnar nerve CSAs correlate with slowing of the conduction velocity on EDSs, and those with positive EDSs have larger nerve sizes than those with negative tests.

Association between electrodiagnosis and neuromuscular ultrasound in the diagnosis and assessment of severity of carpal tunnel syndrome

BACKGROUND

Neuromuscular ultrasound plays an increasing role in diagnosing carpal tunnel syndrome (CTS). There are limited data supporting the correlation between the electrodiagnostic studies and ultrasound measurements in CTS.

OBJECTIVE

To assess the association between different electrodiagnostic severities and ultrasound measurements of the median nerve in CTS.

DESIGN

A retrospective cohort study.

SETTING

An academic tertiary care center.

PATIENTS

Patients 18 years or older evaluated with upper limb electrodiagnostic studies and neuromuscular ultrasound.

MAIN OUTCOME MEASUREMENT

Ultrasound measurements of the median nerve cross-sectional area (CSA) at the wrist and the calculated wrist-to-forearm ratio (WFR) were compared with the electrodiagnostic severity (normal, mild, moderate, and severe). Mean analysis and analysis of variance test (α = 0.05) were performed to assess the association.

RESULTS

A total of 1359 limbs were identified. There was a statistically significant association between electrodiagnostic severity of CTS and median nerve CSA at the wrist (p < .001), as well as the WFR (p < .001). The mean median nerve CSA at the wrist and WFR were 7.01 ± 2.06 mm2 (95% CI: 6.80-7.20) and 1.24 ± 0.36 (95% CI: 1.16-1.24) in electrodiagnostically normal median nerves, 10.47 ± 2.82 mm2 (95% CI: 10.25-10.75) and 2.06 ± 0.67 (95% CI: 2.04-2.16) in electrodiagnostically mild CTS, 12.95 ± 4.74 mm2 (95% CI: 12.41-13.59) and 2.49 ± 1.04 (95% CI: 2.37, 2.63) in electrodiagnostically moderate CTS, and 14.69 ± 5.38 mm2 (95% CI: 13.95-15.44) and 2.71 ± 1.02 (95% CI: 2.56-2.84) in electrodiagnostically severe CTS, respectively.

CONCLUSION

This study suggests a direct association between electrodiagnostic severity and ultrasound measurements of the median nerve in patients with suspected CTS.

Final 1-Year Results of the TUTOR Randomized Trial Comparing Carpal Tunnel Release with Ultrasound Guidance to Mini-open Technique

Background

Studies comparing carpal tunnel release with ultrasound guidance (CTR-US) to mini-open CTR (mOCTR) are limited. This randomized trial compared the efficacy and safety of these techniques.

Methods

In this multicenter randomized trial, patients were randomized (2:1) to unilateral CTR-US or mOCTR. Outcomes included Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS) and Functional Status Scale (BCTQ-FSS), numeric pain scale (0-10), EuroQoL-5 Dimension 5-Level (EQ-5D-5L), scar outcomes, and complications over 1 year.

Results

Patients received CTR-US (n = 94) via wrist incision (mean 6 mm) or mOCTR (n = 28) via palmar incision (mean 22 mm). Comparing CTR-US with mOCTR, the mean changes in BCTQ-SSS (-1.8 versus -1.8; P = 0.96), BCTQ-FSS (-1.0 versus -1.0; P = 0.75), numeric pain scale (-3.9 versus -3.8; P = 0.74), and EQ-5D-5L (0.13 versus 0.12; P = 0.79) over 1 year were comparable between groups. Freedom from scar sensitivity or pain favored CTR-US (95% versus 74%; P = 0.005). Complications occurred in 2.1% versus 3.6% of patients (P = 0.55), all within 3 weeks postprocedure. There was one revision surgery in the CTR-US group, and no revisions for persistent or recurrent symptoms in either group.

Conclusions

CTR-US and mOCTR demonstrated similar improvement in carpal tunnel syndrome symptoms and quality of life with comparable low complication rates over 1 year of follow-up. CTR-US was performed with a smaller incision and associated with less scar discomfort.

Changes in Cross-sectional Area of the Median Nerve and Boston Carpal Tunnel Questionnaire Scores After Carpal Tunnel Release

BACKGROUND

We hypothesized that postoperative Boston Carpal Tunnel Questionnaire (BCTQ) scores and ultrasound (US) measurements of the median nerve cross-sectional area (CSA) at the distal wrist crease are significantly decreased at 2-week, 6-week, and ≥ 6 months follow-up appointments, compared with baseline values.

METHODS

This study was a retrospective chart review of patients who presented to a single hand clinic with evidence of carpal tunnel syndrome over a 6-year period (2014-2020). Patients received baseline US measurements of the median nerve CSA as well as completion of the BCTQ, and for the patients who underwent carpal tunnel release (CTR), postoperative US measurements and questionnaire scores were obtained at 2 weeks, 6 weeks, or ≥ 6 months postoperatively.

RESULTS

This study included 224 separate wrists. Median Nerve CSA measurements were 13.2 ± 4.5 mm2 at baseline, 11.9 ± 3.6 mm2 at 2 weeks postoperatively, 11.6 ± 4.5 mm2 at 6 weeks postoperatively, and 11.7 ± 4.3 mm2 at 6 months or more (P = .002). The BCTQ Symptom Severity Scale scores were 3.14 ± 0.76 at baseline, 1.76 ± 0.63 at 2 weeks, 1.68 ± 0.70 at 6 weeks, and 1.41 ± 0.64 at 6 months or longer (P < .001). The BCTQ Functional Status Scale scores were 2.56 ± 0.89 at baseline, 2.03 ± .1.0 at 2 weeks, 1.65 ± 0.77 at 6 weeks, and 1.36 ± 0.61 at 6 months or longer (P < .001).

CONCLUSIONS

These findings demonstrated a sustained decrease in median nerve CSA and patient-reported outcomes following CTR at 2 weeks, 6 weeks, and between 6 and 12 months.

Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome

BACKGROUND

This study aimed to demonstrate the effectiveness of our new diagnostic chart using point of care ultrasound combined with CTS-6 for diagnosing idiopathic carpal tunnel syndrome.

METHODS

We conducted a retrospective analysis of the data of patients who visited our department and received point of care ultrasound combined with CTS-6 from 2020 to 2023. Data regarding age, sex, initial and final diagnosis, cross-sectional area of the median nerve, CTS-6 score, and electrodiagnostic severity were obtained and statistically analyzed.

RESULTS

Of the 177 wrists included in our study, 138 (78 %) were diagnosed with carpal tunnel syndrome, while 39 (22 %) were not (non-carpal tunnel syndrome). With our diagnostic method, 127 wrists (72 %) were diagnosed initially with carpal tunnel syndrome, 23 wrists (13 %) with non-carpal tunnel syndrome, and the rest 27 wrists (15 %) as borderline. Our initial diagnoses of carpal tunnel syndrome and non-carpal tunnel syndrome were maintained in all cases except for two. Cross-sectional area, CTS-6 score, and electrodiagnostic severity showed a positive correlation. A post hoc analysis showed that the new scoring system (CTS-6 score + 2 × cross-sectional area) with a cutoff value of 31.25 points showed a sensitivity as high as 95 % and a specificity of 100 %.

CONCLUSIONS

Our findings suggest that most suspected idiopathic carpal tunnel syndrome cases can be diagnosed correctly using the diagnostic chart. Although additional tools, including electrodiagnostic studies, may be needed for borderline cases, the use of point of care ultrasound combined with CTS-6 may be a recommendable first-line confirmatory test because point of care ultrasound and CTS-6 could be complementary tools, and this chart may be especially beneficial for atypical or outlier cases.

LEVEL OF EVIDENCE

Diagnostic III.